Well liner

ABSTRACT

A well liner for use in lining a well penetrating a producing formation and formed from an elongated tubular member having a plurality of spaced-apart holes formed therein with a pin having a diameter less than the diameter of the hole extending through each of the holes with a head section on each end of the pin larger than the hole to maintain the pins loosely fitting in the holes. A tool is provided for use in moving the pins to clean the liner.

United States Patent [56] References Cited UNITED STATES PATENTS 2,175,540 10/1939 ONeill.........................

[72] inventor Albert E. Campbell TafLCalil.

[21] AppLNo. 41,387

[221 Filed 71x11 27 77 21 -1] //7// 66166 66 66 Ill/Dill.

11/1951 Primary Examiner-David H. Brown & Md m is f C. n Cm "m MSB 004 444. 999 111 III 823 1 427 8 2 245 24 2 2 3- 222 May 28, 1970 [45] Patented Sept. 7, 1971 [73] Assignee Chevron Research Company San Francisco, Calif.

AttorneysA. L. Snow, F. E. Johnston, R. L. Freeland, Jr. and

E. J. Keeling [54] WELL LINER 7 8 6 HZMOHQ 2/ 2 n n 6 4 00 6 6 6 b6 m n W n m m m m0 u "7 n n "l n W m 3 m m m mu m l 0 mt c m CS m k 4 I F l l l. 2 l 0 5 5 5 l .l. .l

PATENIEDSEP new INVENTOR ALBERT E. CAMBELL WELL LINER BACKGROUND OF THE INVENTION The invention relates to a well liner for use in lining a producing interval of a well penetrating an oil producing formation and, more particularly, the invention relates to a well liner having spaced-apart holes formed therein and a loosely fitting pin extending through each of the holes and having flanged head sections to maintain the pins loosely fitting within the holes.

The oil producing zone of a producing well is often lined with a hollow tubular member having a series of spaced-apart slots or perforations formed therein. The well liner acts to prevent sand and other undesirable material from flowing into the well while at the same time, permitting hydrocarbon flow through the slots or perforations into the well. In many instances, however, after oil is produced for some time, the slots or perforations tend to plug up due to accumulations of tarry substances asphaltenes, sand and other matter. The opening sometimes become partially or totally plugged and thus greatly hinder or entirely prevent oil flow into the well.

Heretofore the prior art has attempted to solve this plugging problem by cleaning out the openings. Thus mechanical scratching devices with or without chemical solvents have been utilized in attempts to reopen the closed openings. The mechanical cleaning devices are separate tools which are run down the well usually by wire line and have sharp protrusions which are supposed to enter and open the slots or perforations. There is, however, a serious problem in getting the tool aligned so that the protrusions will enter the openings. An attempt as disclosed in US. Pat. No. 2,345,027 has been made to overcome this problem by placing movable wires in the holes of a well liner. The wires are flexed by a cleanout tool to remove accumulations from the holes. None of the above solutions has proved entirely satisfactory and there is still need for a well liner which is effective in producing oil and which can be easily and surely cleaned by mechanical means.

SUMMARY OF THE INVENTION The present invention is directed to a device useful to line a producing formation penetrated by a well. The liner is formed of a hollow tubular member having a plurality of spaced-apart holes in its wall. A pin extends loosely through each of the holes. Each pin has head sections on both ends to capture it into the hole. A tool member is insertable within the liner for contacting the interior heads of the pins to move the pins to loosen material between the pins and the tubular member to improve oil passage between the pins and the tubular member.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is an elevation view, with portions broken away for clarity of presentation, illustrating the preferred embodiment of apparatus assembled in accordance with the present invention.

FIG. 2 is an enlarged view, partially in section, of a portion of the apparatus shown in FIG. 1.

FIG. 3 is a perspective view showing a portion of the apparatus of FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIGS. 1-3, a well liner is shown in position adjacent a producing formation 12. Oil is produced through openings 14 in the liner from the formation into the interior of the well, and thence by suitable means, such as a pump, to the surface. The holes 14 in the liner 110 permit oil to pass while preventing sand from coming into the well. In accordance with the invention, the well liner 10 has a plurality of spaced-apart holes M formed in its wall. In each of the holes M, a pin 16 is Rositioned in loosely fittingI relationshifi with the side of the ole. Thus the pm is sized arge enoug so that oil may pass through the space between the well liner and the pin, yet small enough to prevent undo amounts of sand or the like from entering the well.

The pin 16 is retained in position on the well liner by suita ble retaining means. For example, head sections 18 and 20 are connected to each end of a pin to maintain it in loosely fitting relationship within a hole 14 of the liner. The head sections 18 and 20 have at least one portion having a diameter greater than the diameter of the holes 14 so as to maintain the pin within the holes. The rim of the head sections 18 and 20 may be castellated such as indicated by the numeral 22 to permit better passage of oil into the interior of the liner.

The well liner containing the loosely fitting pins as described above is run into a well adjacent a producing formation. The diameter of the well penetrating the producing formation is made large enough to permit passage of the exterior head sections of the pins. After the well liner containing the pins is run, cement may be injected down the well and squeezed into the annular space between the outside of the well liner and the well wall. This technique is well known in the art and will not be described here. After the cement sets and the other suitable well completion work is accomplished, the well is in a condition to be produced.

After the well has been produced for some time, the openings in the well liner may become partially or totally plugged and it is then desirable to improve flow through the holes of the well liner. This is accomplished in accordance with the invention by means of disturbing the position of the pins by contacting the inner head section 18 of the pins with a suitable tool. For example, a tool member 24 suspended from wire line 26 may be utilized to contact the head sections. The tool 24 is reciprocated in the hole to repeatedly contact the had sections and to thus rattle the pins within the holes. The tool 24 has on its exterior surface a number of protrusions 28 suitable for contacting the head sections 18 of the pins when the body member 24 is lowered into the well adjacent the well liner and is moved up and down by means of wire line 26. The protrusions 28 will contact the head sections 18 of the pins 16 and cause the pins to be displaced within the holes of the well liner. In this manner, blockages of the passages into the well is corrected. After such an operation it may be desirable to bale or to otherwise clean out debris from the well before returning it to production.

Although only certain preferred embodiments of this invention have been described in detail, the invention is not to be limited to only such embodiments but rather by the scope of the appended claims.

I Claim:

1. A well liner comprising an elongated tubular member having a plurality of spaced-apart holes formed in its wall, a pin extending through each of said holes, said pins having a diameter less than the diameter of said holes to provide a loose fit of said pins in said holes, a head section on each end of said pins, said head section having a diameter greater than the diameter of the holes to maintain said pins in said holes.

2. The apparatus of claim I further characterized in that the head section has portions of reduced diameter to allow oil to more readily flow past said head sections.

3. The apparatus of claim 2 further characterized by a tool insertable into said tubular member for contacting the interior head of said pin to move said pin to improve oil passage between said pin and said tubular member.

4. The apparatus of claim 3 further characterized in that said tool has a series of protrusions for contacting the heads of said pins. 

1. A well liner comprising an elongated tubular member having a plurality of spaced-apart holes formed in its wall, a pin extending through each of said holes, said pins having a diameter less than the diameter of said holes to provide a loose fit of said pins in said holes, a head section on each end of said pins, said head section having a diameter greater than the diameter of the holes to maintain said pins in said holes.
 2. The apparatus of claim 1 further charaCterized in that the head section has portions of reduced diameter to allow oil to more readily flow past said head sections.
 3. The apparatus of claim 2 further characterized by a tool insertable into said tubular member for contacting the interior head of said pin to move said pin to improve oil passage between said pin and said tubular member.
 4. The apparatus of claim 3 further characterized in that said tool has a series of protrusions for contacting the heads of said pins. 